The present disclosure herein relates to a calibration device and method for calibrating a three-dimensional imaging equipment.
A three-dimensional imaging equipment may capture an image of an object while revolving in a predetermined circular orbit. When a gantry of the imaging equipment revolves in an accurate circular orbit, positional relationships among a source, a detector, and a subject may be briefly defined with several parameters (e.g. parameters such as a gantry rotation angle, a distance between the source and detector, a distance between a source and a rotation axis, and a detector rotation angle). When the parameters are accurate, a two-dimensional image detected by the detector may be easily reconstructed to a 3-dimensional image. However, since the gantry is large and heavy, it is not easy to make the gantry revolve in a perfectly circular orbit. For example, since a structural deflection or modification easily occurs, the positional relationships among the source, detector, and subject are not easily described with the gantry rotation angle and several parameters. Despite of occurrence of the structural deflection or modification, when the three-dimensional image is reconstructed with the gantry rotation angle and several parameters, an reconstructed image may be blurred.
However, even when positional relationships between an X-ray source, a detector, and a subject are not described precisely with a rotation angle and several parameters, when a rotational trajectory of the gantry is sufficiently repeatable, the imaging equipment may be simply, precisely, and geometrically calibrated.